Explanation of File Size

[ydekmekji]

I had two recordings today:

Recording #1--3 Hours on PVR USB II--File is 6Gigabyte
Recording #2--5 Hours on PVR 150--File is 15Gigabytes

They both are on Medium recording Setting.

This doesn't make sense to me. Both files turned out great, but it still doesn't make sense to me! It seems like the 5 hour one should be maybe 10-12 Gigs... Anyone have any thoughts?

[ydekmekji]

Can anyone give me insights into this? Maybe how file size works on your computer??

[bluesxman]

Isn't down to the type of recording? I.E. Action/Sports will be larger as there are more changes in each frame. Does this fit with what these recordings are?

[j3flight]

Can anyone give me insights into this? Maybe how file size works on your computer??

You're probably recording using Variable Bitrate which adjusts between a minimum and a maximum depending on the amount of motion in the scene.

If your first recording was, say, a news broadcast (where the picture is often steady and not moving) and your second was an action movie (where the picture is constantly in flux) those file sizes would make sense. It's kind of an extreme case, but that's my first guess.

If I record the same show movie twice with variable bitrate, it comes out almost identical because the only difference is the commercials. If I record a different movie (of same length) it is often different by 10% or more.

Jason

[j3flight]

Basically, it comes out to the fact that your first recording is 2GB/hour and your second is about 3GB/hour.

That is a relatively large difference, but seems reasonable using the same VBR settings.

Jason

[ydekmekji]

That's helpful--i am using vbr. However, here's what's interesting: They both are of the Live 8 concert (on two different channels). I wonder if the scene changes (that were more frequent on one of the chanels) on one of the channels caused the difference.

[j3flight]

Could be.

Or even just camera movement. Pans, fades, etc, etc... All put a hurtin' on MPEG2 because the whole scene is changing. What do you have your bitrate min/max set to?